pcm_mix()

int pcm_mix	(	void *const	pcm_a,
		size_t	size_a,
		void const *const	pcm_b,
		size_t	size_b,
		enum pcm_mix_mode	mix_mode )

#include <include/pcm_mix.h>

Mixes two buffers of PCM data.

Note

Uses simple addition with hard clip protection. Input can be mono or stereo as long as the inputs match. By selecting the mix mode, mono can also be mixed into a stereo buffer. Hard coded for the signed 16-bit PCM.

Parameters

pcm_a	[in/out] Pointer to the PCM data buffer A.
size_a	[in] Size of the PCM data buffer A (in bytes).
pcm_b	[in] Pointer to the PCM data buffer B.
size_b	[in] Size of the PCM data buffer B (in bytes).
mix_mode	[in] Mixing mode according to pcm_mix_mode.

Return values

0	Success. Result stored in pcm_a.
-EINVAL	pcm_a is NULL or size_a = 0.
-EPERM	Either size_b < size_a (for stereo to stereo, mono to mono) or size_a/2 < size_b (for mono to stereo mix).
-ESRCH	Invalid mixing mode.